Transition States and Activation Barriers for [3,3]-Sigmatropic Shift of Allyl Azides

CBS-QB3 and density functional theory studies of the [3,3]-sigmatropic rearrangements of several allylic azides indicate that this reaction is a concerted process that proceeds via a half-chair transition state. The activation barriers for rearrangements of hydroxyl azides are lower than those of the corresponding aliphatic azides. The epoxidations and phenyl azide cycloadditions of allylic azides were also studied.